The iPhone Dev Team has done it again!
With the release of Pwnage Tool 2.0, you can fully jailbreak and unlock the first gen iPhone 2.0 software, as well as jailbreak the iPhone 3G model.
Announcement and download mirrors
As Pwnage Tool 2.0 is currently available only for Mac, Windows users can find here a step-by-step guide for unlocking their iPhone 2.0 with WinPWN.

[...] you have pwned your iPhone successfully with Pwnage Tool 2.0, you don’t need to do it again with 2.0.1. Pwnage Tool 2.0.1 announcement and download [...]
[...] are the instructions for Mac users, and here they are for Windows users. [...]
[...] 24, 2008 by decoding After the release of Pwnage Tool 2.0 and 2.0.1 for Mac, here is the respective release for Windows, Winpwn [...]
Woow , fantastic
also you don need a step by step pwnage thing to make it work, this hack takes a bit more time
does anyone know of a tutorial for using this pwnage 2.0.1? I
I got it, opened but dont know how to run it. It is asking for a software bundle.
@Max: http://iclarified.com/entry/index.php?enid=1557